A Senate Health, Education, Labor, and Pensions Committee hearing on Sept. 17, 2025, centered on the leadership shake-up at the Centers for Disease Control and Prevention and the science behind vaccines for infants. The session followed Health and Human Services Secretary Robert F. Kennedy Jr.’s decision to oust CDC Director Susan Monarez last month and sought to examine the rationale for infant vaccine guidance.
Sen. Rand Paul, R-Ky., used the moment to question the CDC’s infant vaccine recommendations, arguing that the scientific case for vaccinating very young children should be transparently weighed against potential risks. Paul pressed Monarez and Sen. Bernie Sanders about the benefits of vaccinating six-month-old infants and the evidentiary basis for those recommendations. He asserted that the discussion must address “what is the science in favor of giving the vaccine to a 6-month-old, and what are the benefits from that? And there is no benefit of hospitalization or death. And then what would the risks of that vaccine be? We have large population studies of the risks of the vaccine in younger people.”
What followed was a tense back-and-forth in which Paul also questioned the necessity of certain vaccines for newborns. He asked, “What is the medical reason to give a Hepatitis-B vaccine to a newborn whose mom has no Hepatitis?” Sanders interjected as Monarez tried to answer, and Paul pressed the point further, arguing that the burden should be on the agency to prove the medical value of vaccines for infants rather than on the public to accept them by default.
When we're discussing the science here, we have to discuss what is the science in favor of giving the vaccine to a 6-month-old, and what are the benefits from that? And there is no benefit of hospitalization or death. And then what would the risks of that vaccine be? We have large population studies of the risks of the vaccine in younger people.
What is the medical, scientific reason and proof for giving a newborn a Hepatitis-B vaccine if the mom is Hep-B negative?
Monarez did not directly answer several of Paul’s questions, insisting that the burden of proof rests with the questioner and that her statements would require more time to address in full. She argued that her earlier tenure was defined by adherence to scientific review processes and that public health recommendations should be guided by data and expert input rather than political frames. "You had your time, Bernie, I’ve got mine," Paul shot back at one point as the exchange grew sharp. Sanders repeatedly interjected to steer the discussion back to the science and the agency's decision-making, highlighting the complex balance between evidence and public health guidance.
The hearing underscored bipartisan anger toward the CDC’s vaccine guidance as members questioned whether the agency’s recommendations sufficiently account for risks in infants and the long-term effects of early vaccination. Supporters of the CDC’s public health mission argued that vaccines are a critical tool against preventable diseases and that the agency follows rigorous evaluation of benefits and safety. Critics, however, urged greater transparency and independent review of infant immunization guidance and the leadership decisions surrounding Monarez’s departure.
As the exchange unfolded, lawmakers from both parties demanded a probe into Kennedy’s decision to dismiss Monarez and called for more scrutiny of the CDC’s vaccine guidance for infants. The episode illustrated the tension between political oversight and public health policy at a moment when vaccination strategy remains a contentious issue in U.S. politics.
The hearing concluded without a consensus on whether current infant vaccine guidelines should be altered, and it highlighted the broader debate over how public health recommendations are formed and who ultimately bears responsibility for those decisions. The moment also added to the ongoing conversation about how leadership changes within federal health agencies interact with scientific advisory processes and public trust in health guidance.
